Racing Under Uncertainty: A Boundary Value Problem Approach

In this paper I formulate a continuous time and continuous space version of Harris and Vickers (1987) Racing Under Uncertainty with potentially asymmetric players. To prove the existence and uniqueness of the equilibria, I use a boundary value problem formulation which is novel to the dynamic competition literature. In some cases, I obtain closed-form solutions of the equilibria in which equilibrium strategies exhibit the discouragement effect similar to the one in the original paper.

Bifurcation and dynamic response analysis of rotating blade excited by upstream vortices

Acknowledgements The authors acknowledge the projects supported by the National Basic Research Program of China (973 Project)(No. 2015CB057405) and the National Natural Science Foundation of China (No. 11372082) and the State Scholarship Fund of CSC. DW thanks for the hospitality of the University of Aberdeen.Peer reviewedPostprin

Collateral Shortages, Asset Price and Investment Volatility with Heterogeneous Beliefs

The recent economic crisis highlights the role of financial markets in allowing economic agents, including prominent banks, to speculate on the future returns of different financial assets, such as mortgage-backed securities. This paper in troduces a dynamic general equilibrium model with aggregate shocks, potentially incomplete markets and heterogeneous agents to investigate this role of financial markets. In addition to their risk aversion and endowments, agents differ in their beliefs about the future exogenous states (aggregate and idiosyncratic) of the economy. This difference in beliefs induces them to take large bets under frictionless complete financial markets, which enable agents to leverage their future wealth. Consequently, as hypothesized by Friedman (1953), under complete markets, agents with incorrect beliefs will eventually be driven out of the markets. In this case, they also have no influence on asset prices and real investment in the long run. In contrast, I show that under incomplete markets generated by collateral constraints, agents with heterogeneous (potentially incorrect) beliefs survive in the long run and their speculative activities permanently drive up asset price volatility and real investment volatility. I also show that collateral constraints are always binding even if the supply of collateral assets endogenously responds to their price. I use this framework to study the effects of different types of regulations and the distribution of endowments on leverage, asset price volatility and investment. Lastly, the analytical tools developed in this framework enable me to prove the existence of the "generalized" recursive equilibrium in Krusell and Smith (1998) with a finite number of agents.

Innovation by Entrants and Incumbents

We extend the basic Schumpeterian endogenous growth model by allowing incumbents to undertake innovations to improve their products, while entrants engage in more “radical” innovations to replace incumbents. Our model provides a tractable framework for the analysis of growth driven by both entry of new firms and productivity improvements by continuing firms. Unlike in the basic Schumpeterian models, subsidies to potential entrants might decrease economic growth because they discourage productivity improvements by incumbents in response to reduced entry, which may outweigh the positive effect of greater creative destruction. As the model features entry of new firms and expansion and exit of existing firms, it also generates a non-degenerate equilibrium firm size distribution. We show that when there is also costly imitation preventing any sector from falling too far below the average, the stationary firm size distribution is Pareto with an exponent approximately equal to one (the so-called “Zipf” distribution”)